ok, the pump adds a negligible amount of heat to your fluid (it is a result of imparting work to the fluid). it is nothing that you should worry about or account for.
you want your radiator before your reservior because it gives the fluid additional time to cool in the res before being used again. the only advantage that i could see putting the rad before the blocks is that the fluid may be more likely to go turbulent (which is a good thing for heat transfer, a bad thing if you dont have alot of pump head). but it would actually be better for your system for the fluid to go turbulent over the blocks as that is truely where heat removal matters.
you want your radiator before your reservior because it gives the fluid additional time to cool in the res before being used again. the only advantage that i could see putting the rad before the blocks is that the fluid may be more likely to go turbulent (which is a good thing for heat transfer, a bad thing if you dont have alot of pump head). but it would actually be better for your system for the fluid to go turbulent over the blocks as that is truely where heat removal matters.